This WordPress PHP snippet creates a metabox for all pages/posts that contains definitions for user entered shortcodes.

shortcode-defintions-metabox-content.php

<?php 
	// Enqueue Thickbox Assets
	add_thickbox(); 
	
	// Define shortcodes
	
	// Setup array
	$shortcodes = array();
	
	// Add a shortcode to the shortcodes array
	$shortcodes[] = array(
		'code'        => '[faqs category="all"]',
		'description' => 'Displays FAQs created in the dashboard on the frontend of the site, optionally filtered by category.',
		'params'      => array(
			'category' => array(				
				'type'       => 'string',
				'definition' => '(Optional) The name of the category.',
				'default'    => '"all"'
			)
		)
	);
?>

<div id="shortcode-definitions-metabox" class="shortcode-definitions-metabox" style="display:none;">
	<?php if( $shortcodes ) : ?>
		<h1 style="margin-bottom: 2em;">Shortcodes</h1>
		<dl class="shortcode-definitions-metabox_list">
			<?php foreach( $shortcodes as $shortcode ) : ?>
				<dt>
					<code>
						<?php echo $shortcode['code']; ?>
					</code>
					<p>
						<?php echo $shortcode['description']; ?>
					</p>
				</dt>
				<dd>
					<h3>
						Parameters
					</h3>
					<?php if( $shortcode['params'] ) : ?>
						<?php foreach( $shortcode['params']  as $param => $details ) : ?>
							<div style="margin-bottom: 1em;">
								<code>
									<?php echo $param; ?>
								</code>
								<div>
									(<?php echo $details['type']; ?>) - <?php echo $details['definition']; ?>
								</div>
								<em>
									Default: <?php echo $details['default'] ? $details['default'] : 'None'; ?>
								</em>
							</div>
						<?php endforeach; ?>
					<?php else : ?>
						None
					<?php endif; ?>
				</dd>
			<?php endforeach; ?>
		</dl>
	<?php else : ?>
		<p>No shortcodes found</p>
	<?php endif; ?>
</div>

<a href="#TB_inline?width=600&height=550&inlineId=shortcode-definitions-metabox" class="thickbox">View Shortcodes</a>	

shortcode-metabox.php

<?php
// Outputs the metabox in the dashboard
function iansvo_shortcode_metabox() {
    add_meta_box( 
    	'shortcode-definitions',
    	__( 'Shortcode Definitions', 'fabent-parent' ), 
    	'iansvo_shortcode_metabox_content', 
    	array('post', 'page'),
    	'side',
    	'high'
    );
}
add_action( 'add_meta_boxes', 'iansvo_shortcode_metabox' );

function iansvo_shortcode_metabox_content() {
	ob_start();
	
	include get_template_directory() . '/inc/shortcode-metabox-content.php';
	
	echo ob_get_clean();	
}